The importance of sensory feedback from the oral region in the control of speech production is under investigation. Research is in progress that studies the perceptual, physiologic and acoustic effects on "normal speech" of oral sensory deprivation; the integrity of the oral sensory system in persons with atypical speech patterns and the role of the sensory systems during stages of speech acquisition. It is anticipated that the insights gained through this research will be of value in the construction of a model of the speech control mechanism.